by Kelly Kennedy, USA TODAY

by Kelly Kennedy, USA TODAY

WASHINGTON - The government's top health technology guru has stepped down from his role leading the Centers for Medicare and Medicaid Services through the implementation of the Affordable Care Act.

When asked if Tony Trenkle, chief information officer and director of the office of Information Services, had been asked to step down after the technology problems with the new federal health exchange, an official refused to confirm or deny the possibility.

"Tony made a decision that he was going to go to the private sector, and that is what our COO announced yesterday," said CMS spokeswoman Julie Bataille. "I don't have anything further to add."

Trenkle has led the department since 2005 and oversaw implementation of the Health Insurance Portability and Accountability Act, as well as a yearly IT budget of about $1 billion.

CMS quickly filled Trenkle's position with an internal candidate, Dave Nelson, director of the Office of Enterprise Management.

Wednesday afternoon, President Obama met with Democratic senators to brief them about progress made with the site, as well as what still needs to be fixed. He asked for input from the senators' constituents about the website.

In a Senate hearing Wednesday morning, Health and Human Services Secretary Kathleen Sebelius said the government would release enrollment numbers for HealthCare.gov next week. She expects those numbers to be low. She said officials always expected low numbers, just as Massachusetts saw in the beginning months of implementation of its exchange.

Bataille said the website was working slowly Wednesday because of a problem with the marketplace application, but it continues to improve.

"We believe enrollment will increase over time," Bataille said. "We believe that consumers will have ample time to enroll in the current six-month enrollment period."

The data hub, where consumers' applications and eligibility requirements are verified, is performing well, she said.

Tuesday night, technicians added a "series of new software releases that were intended to create more than a doze fixes," she said. People know immediately if their information has been properly entered, agents and navigators can find incomplete applications more quickly to help consumers enroll, and the electronic signature page is easier to use.

"We are on track to have the site working smoothly for the vast majority of users by the end of the month," Bataille said.